3.1.3 Surfactant:amphiphilic properties 3.1.3 Surfactant:amphiphilic properties As the concentration of the surfactant is Surfactant properties:Aggregation raised in water.the bulk concentration and the number of molecules in the interface are increased. Cn(云时CC5ean6d eG■en At a certain point.both the surface and equibttum wth thn miceles. the bulk phase become saturated and if more amphiphile is added to the system Monomer concentration the molecules aggregate to form micelles. The concentration of surfactant at Surface tension which micelle fomation occurs is called the critical micelle concentration. CMC CMC,and the number of molecules Surfactant Concentration forming each micelle is called the eggregation number. 年中 Different types of aggregates depending on the SA 3.2.Surfactant:solubilization concentration The aggregates or micelles of a surfactant have the ability of increasing the solubility of slghtly soluble substances.The non-polar molecules of the slightly soluble substance locate into the non-polar core of the miceles. Lysroncal or Hos-snaped Concertration 88888888#88# 888中年0布年中 ● C Biametar Surfactant Concentation 古 6
6 3.1.3 Surfactant: amphiphilic properties 3.1.3 Surfactant: amphiphilic properties Different types of aggregates depending on the SA concentration 3.2. Surfactant: solubilization
3.2.Surfactant:solubilization 3.2.Surfactant:solubilization Solubilization (as micelle formation)is a dynamic Micelle core: process.The solubilized substance is in equllibrium hydrocarbon,suitable for the lipophilic material to with the non-solubilized fractien. be incorporated in thus to be dissolved. Solubilization Equilibrium: The solubilization can be considered as a partitioning process between the [Drao] Ks [Drm] aqueous enviroment and the Lumen (free drug) (micellar-bound drug) micellar phase. Taking effect drug depot,sustained release In this way.if the non-solubilized solute is removed from the aqueous enviroment.part of the solubilized molecules will exit from the micelles to re-establish the equilibrium. 3.3 Properties of pharmaceutical solubilized systems 4.1 Suspension 1.Contributions: Why we choose suspension to deliver a drug? .To improve the apparent solubility: advantages and disadvantages:given route anti-neoplastic and anti-HIV agents etc. ·To improve the sta bility of the drug in water How to formulate Formulation consideration 2.Potentially Negative influence on the action of preservatives How to prepare and quality-control? 3.Limitations: lab scale and pilot scale;process validation 4.Safety consideration:chronic toxicity and given route How to evaluate Evaluation:Safety,Stability and Efficiency >
7 3.2. Surfactant: solubilization 3.2. Surfactant: solubilization Micelle core: hydrocarbon, suitable for the lipophilic material to be incorporated in thus to be dissolved. Solubilization Equilibrium: [Draq] Ks [Drm] (free drug) (micellar-bound drug) Taking effect drug depot, sustained release 3.3 Properties of pharmaceutical solubilized systems 1.Contributions: z To improve the apparent solubility: z anti-neoplastic and anti-HIV agents etc. z To improve the stability of the drug in water 2. Potentially Negative influence on the action of preservatives 3. Limitations: 4. Safety consideration: chronic toxicity and given route 4.1 Suspension Why we choose suspension to deliver a drug? advantages and disadvantages; given route How to formulate ? Formulation consideration How to prepare and quality-control? lab scale and pilot scale; process validation How to evaluate ? Evaluation: Safety, Stability and Efficiency